Kendra Wilkinson (left) and Crystal Harris
Michael Williams/Startraks; INF
08/02/2011 at 08:00 AM EDT
remembers landing in hot water for exposing her days as Hugh Hefner's girlfriend in her tell-all Sliding Into Home
– but the former Girls Next Door
star believes her comments were far less hurtful than those
of Hef's former wife-to-be
, Crystal Harris.
"Her situation is a lot more harsh," Wilkinson, 26, told PEOPLE at Monday's NBCUniversal Press Tour All-Star party in L.A. "She was about to get married
to him. I would have never agreed to get married to him."
Even though Wilkinson's book laid bare her sex-life with the Playboy
mogul, 85, she says she would never go out of her way to hurt Hef the way Harris, 24, did when she gossiped with Howard Stern last week about Hefner's sexual prowess
– or lack thereof
"We both knew our place," Wilkinson says of her and Hefner. "He knew that we were friends. I knew that we were friends. But to [plan to] get married and then be a backstabber to someone like that – to take it to that level and then go and backstab, that's, like, cruel, you know?"
Being someone who has once experienced sheltered life in the Playboy Mansion, Wilkinson says she initially related to Harris's venting. But that all changed once the runaway bride turned on Hefner.
"At first I was really proud," Wilkinson says. "I was like, 'Wow, she's being classy about things.' But then lately, she's just like totally running her mouth and it's hard."